Grinding-mill.



J. A. BAIR.

GRINDING MILL. APPLICATION HLED' MAR- I, ma.

193mm? r Patented Apr, 22, 1919.

2 SHEETSSHEET l.

J. A. BAIR.

GRIQNDIING MILL.

APPLICATION FILED MAR.1,19I8.

Patented Apr. 22,1919.

2 SHEETS-SHEET 2- JAMES A. JBAIR, 0F TAT/EA, FLORIDA.

GRINDING-MILL.

nearest.

Specification of Letters Patent.

Patented Apr. 22, 119il9.

Application filed March 1, 1918. Serial No. 219,872.

To all whom it may concern:

Be it known that I, JAMEsA. lBAIR, a c1tizen of the United States, residing at Tampa, in the county of Hillsborough and State of Florida, have invented certain new and useful Improvements in Grinding-Mills; and I do declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

The principal object of the present invention is to provide a novel form of mill which although being comparatively simple andinexpensive, and requiring little power for its operation, will produce a maximum amount of work in a minimum time.

In carrying out the above object, the shell in which the material is ground is formed of a plurality of super-imposed rings which may readily be detached to permit their grinding means to be sharpened; and a further object is to provide means whereby any tendency on the part of the rings to rotate, due to operation of the grinding rotor, will be utilized to more securely hold said rings in place.

A retainer is provided for the aforesaid rings and is supported from the hopper of the machine, a still further object being to provide means whereby any tendency on the part of said retainer to rotate, will be utilized to more firmly secure it to the hopper.

I proved mill;

2 is a central vertical section; Fig. 3 is a horizontal section on the plane of the line Fig. 3-3 of Fig. 2;

Fig. 4 isa disassembled perspective view showing the hopper. the rotor, a pair of griding rings, and the retainer of these rings; and

Fig. 5 is a perspective view showing more particularly the lever for raising the thrust shaft which normally depresses the drive shaft upon which the rotor is carried.

Briefly speaking, the improved machine consists of a hopper H, a shell S. a rotor R, and numerous details yet to be described.

The hopper H is preferably in the form of a substantially horizontal ring rigidly supported by legs or the like 1 whose lower ends are preferably secured to a base 2. A suitable inlet chute 3 rises from the hopper H and may either be cast integrally therewith or formed separately as may be most desirable.

The shell S is positioned beneath the hopper H and includes a plurality of superimposed rings 4 which vary in size from one end of the shell to the other, so that an inverted cone-shape is imparted to the latter. The inner faces of the rings 4 are provided with grinding ribs 5 or with any other preferred grinding means, while the periphcries of said rings are formed with annular oustanding flanges 6 whose edges are shaped to form a plurality of spiral cams 7 which engage vertical bars 8 of a retaining means within which all of the rings 4 are held. This retaining means includes the inclined bars 8, an upper comparatively large annulus 9 and a lower relatively small annulus 10, the bars in question being joined integrally or otherwise to said parts 9 and 10. The rotor R has the tendency to rotate the rings 4, but any tendency on the part of these rings to so turn, is utilized to wedge the cams 7 tightly against the bars 8, so that the rings are more tightly held within the retainer. This is a highly important feature, since although a sectional construction may be employed, that is the shell may be composed of a plurality of rings, chattering and other undesirable results are prevented. Obviously. the sectional construction is of great advantage since it insures ease of assembly. ease in sharpening the grinding means 5, and permits worn-out sections to be renewed without interfering with the others. For illustrative purposes, the hopper H is shown provided with a depending flange 11 fitting within the upper annulus 9 and resting on the upper ring 4 to retain the series of rings in place.

The rotary tendency of the rings 4 exerts a similar tendency on the retainer composed of the parts 8, 9 and 10, and in order to utilize this tendency to more rigidly secure said retainer in place, the periphery of the an nulus 9 and the hopper H are provided with coacting inclined cam lugs 12 and 13 respectively, the hopper lugs 13 depending below the lower edge of the hopper as featured clearly in Figs. 1 and 4. To prevent possible retrograde motion of the retainer, a set screw 14 or other preferred means is passed through the ring 9 as shown.

The rotor B may be constructed of one piece or of several sections, the latter construction being preferable for the reasons above given in connection with the rings 4, and the periphery of this rotor may be provided with any suitable driving means 15, or in some instances may be practically smooth, according to the nature of the work to be performed. The same maybe said of the inner surfaces of the rings 1, although these parts will in most cases be roughened in some suitable manner. Regardless of the exact details of construction, the rotor R is by preference threaded at 16 upon the lower end of a substantially vertical drive shaft 17, the threads running-in such-a direction as to maintain at all times a tight connection between the rotor and shaft. Shaft 17 is rotatably mounted in bearings 18 on the outer ends of horizontal arms 19 which project from a rigid standard 20, said standard being rigidly secured to and rising from the hopper H. Any preferred means such as a belt pulley 21 may be employed for rotating the shaft 17, and for the purpose of normally thrusting this shaft downwardly to move the rotor 33 to operative position, and for raising the shaft and rotor when necessary, the following arrangement is employed.

A thrust shaft 22 is positioned above and vertically alined with the drive shaft 17, the two shafts being connected for bodily movement upwardly and downwardly, by a thrust bearing 23. It thus follows that when shaft 22 is either raised or lowered, shaft 17 and rotor R are correspondingly shifted. A guide 24 is provided for the thrust shaft 22, said guide being carried on the front end of an arm 25 which extends forwardly from the standard 20, and immediately above this guide an adjusting wheel 26 is threaded on the shaft in question, a jam nut 27 being provided for looking said adjusting wheel against accidental rotation after proper adjustment. thereof. A coiled sprin 28 thrusts downwardly upon the jam nut 2 the upper end of said spring bearing against an adjusting nut 29 threaded in a guide 30, said guide being carried on the front end of a lateral arm 31 extending from the standard 20. By this means, the tension of the spring may be varied to depress the rotor with greater or less force. For

raising the rotor when necessary, a cam 32 operates between the adjusting wheel 26 and the guide 24.

The cam 32 is by preference shaped substantially as seen in Fig. 5 and coacts with a similarly formed portion of the guide 24, said cam and guide being each formed with a depressed portion 33 and a rise 34, these depressions and rises interengaging each other when the cam is in an idle position, so that by keying the cam on the thrust shaft 22, rotation of the latter is prevented. This keying must of course be such as to permit vertical movement of the shaft through the cam as the adjusting wheel 26 is operated. F or turning the cam 32 in one direction or the other to quickly raise the rotor clear of the shell whenever necessary, an arm 36 is shown joined integrally with said cam, and an operating rod 37 is by preference pivoted to the outer end of said arm, whereby the cammay be operated from a remote point and the feed automatically cut off.

In operation, the material to be ground is deposited in the hopper H through the chute 3, and by proper adjustment of the wheel 26, the rotor R is moved into such relation with the shell S as to grind the material to the required mesh. Whenever necessary, the tension of the spring 28 may be varied by adjusting the nut 29, and when it is required to raise the rotor clear of the shell, it is ing all sorts of material, but the details of construction will yary slightly according to the work to be performed. lln all cases, however the machine will be highly efficient and durable, even though comparatively simple and inexpensive. Particular emphasis is laid upon the general compact organization of the machine, upon the cams 6 for holding the grinding rings 4 tightly in the retainer, upon the lugs 12 and 13 for rigidly securing said retainer to the hopper. and upon the cam 32 and the associated ad usting means of the thrust shaft. Since prob a'bly the best results are obtained from the several details shown and described, these details are by preference employed, but within the scope of the invention as claimed, numerous minor changes may well be made.

I claim:

1. A grinding mill comprising a tapered rotOr with its smaller end disposed downwardly, a tapered grinding shell in which said rotor is received, 'said shell being formed of super-imposed rings of difl'ereach of said rings having a a peripheral flange and the outer edges of the several flanges being shaped to form said spiral cams.

surrounded by said grinding rings and exerting a tendency to. rotate these rings as well as said retainer, means for utilizingany rotating tendency ofsaid grinding rings to more securely hold them in said retainer, andmeans for supporting said retainer from said supporting ring and for utilizing any rotating tendency of the former to more forcibly secure it to the latter.

5. In a mill, a supporting ring, a rotor, .a said shell whose upper end abuts said supporting 3. A grinding mill comprising a plurality ring, said rotor having a tendency to rotate said retainer, inclined cam lugs depending from saidring in contact with the outer side of said retainer to center the latter, and lugs on said retainer engaging said cam lugs to utilize any turning tendency of said retainer to more securely hold it against said supporting ring.

6. A grinding mill comprising a downwardly'tapered rotor, a downwardly tapered shell for said rotor formed of super-imposed rings, a retainer for said shell consisting of an upper comparatively large ring, a smaller lower ring, and inclined bars extending between said upper and lower rings, spiral cams on the peripheries of said rings contacting with said inclined bars to utilize any turning tendency of the rings to thrust them upwardly into proper engagement with the rotor, a supporting ring against Whose lower edge the upper ring of said retainer bears, inclined cam lugs depending from said supporting ring in contact with the outer side of said upper retainer ring to center the latter, and lugs on said upper retainer ring engaging said cam lugs to utilize any turning tendency of the retainer to more tightly engage it with said supporting ring.

7. A retainer for the herein described mill, comprising an upper and a lower'annulus, vertical bars connecting them, and inclined lugs on the periphery of the upper annulus.

In testimony whereof I have hereunto set my hand in the presence of two subscribing witnesses.

JAMES A. BAIR. Witnesses:

WM. H. HAUPT, J. V. MADDEN. 

